《DSP using MATLAB》Problem 6.17

代码：

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%%            Output Info about this m-file

fprintf('\n***********************************************************\n');

fprintf('        <DSP using MATLAB> Problem 6.17 \n\n');

banner();

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%format long;

format short;

fprintf('\n FIR filter DIRECT-form:     \n');

k = [0:6];

b = exp(-0.9*abs(k-3))

a = 1.0

fprintf('\nConvert DIRECT-form to CASCADE-form :     \n');

[b0, Bc, Ac] = dir2cas(b, a) 

fprintf('\nConvert TF-form to SOS-form :     \n');

[sos, g] = tf2sos(b, a)

% ----------------------------------------------------------

% NOTE: linear-phase can not use LATTICE-form

% ----------------------------------------------------------

fprintf('\nConvert DIRECT-form to All-Zero LATTICE-form :     \n');

[Klc] = dir2latc(b) 

fprintf('\nConvert DIRECT-form to FREQUENCY-SAMPLE-form :     \n');

[Cfs, Bfs, Afs] = dir2fs(b) 

% -----------------------------------------

%     START check

% -----------------------------------------

n = [0:7];

delta = impseq(0, 0, 7)

%format long

format  short

hcas = casfiltr(b0, Bc, Ac, delta)

%hltc = latcfilt(Klc, delta)

%hladr = ladrfilt(Klr, Clr, delta)

hdir = filter(b, a, delta)

% -------------------------------------------

%       END check

% -------------------------------------------